Overview. Caffeine is a chemical primarily found in coffee and tea, but which also appears in various sodas, sports drinks and foods. It is a stimulant, therefore causing changes in metabolism as well as increases in focus and energy. Caffeine is addictive and can cause withdrawal following cessation after frequent use.
robot. 1  a machine that resembles a human and does mechanical, routine tasks on command. 2  a person who acts and responds in a mechanical, routine manner, usually subject to another's will; automaton. 3  any machine or mechanical device that operates automatically with humanlike skill.
Definition. A computer is a programmable electronic device designed to accept data, perform prescribed mathematical and logical operations at high speed, and display the results of these operations, all under the control of software.